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package com.srcptit.trainning.thompv.btvn1;
import java.util.Scanner;
/**
 *
 * @author SONY
 */
public class Bai5Muc1
{
     public static void main(String[] args)
     {
         Scanner sc=new Scanner(System.in);
         long f0=1,f1=1,fn=0,n;
         n=sc.nextLong();
         long dem=2;
         if(n==1||n==2) System.out.println(1);
         else while(dem<n)
         {
             fn=f0+f1;
             f0=f1;
             f1=fn;
             dem++;
         }
         System.out.println("Ket qua: " + fn);
     }
}
